Urgent: ZD3400 upgraded firmware version 9.8.3.0.14 could not support wireless mesh, even T301n could not mesh wirelessly

We have a customer using ZD3000, firmware version 9.4.2.0.29 controlling up to 300 units of (EOL) ZF7025 model APs.

We were required to integrate R700, R600 and T301n APs to work with EoL 7025 in Zd3000 but the highest firmware version that could support the Old and New APs is 9.8.3.0.14.

After successful upgrade, we realized the following problems1. The two T301n could not mesh wirelessly, we realized that on the <Monitor> -- <Access Point> -- webpage, that <Mesh Mode> is completely missing

We believe have seen the problem, we upgraded from firmware version 9.4 to 9.8.3.0.14. The aim is to include new devices like T301n, R700 and R600. Now upgrade is running successfully but now we want to mesh T301n(s), we enabled the mesh but on the Monitor AP view, "Mesh Mode" seems hidden or not available.

Please how do we include this Mesh feature of ZD3000 v9.8.3.0.14 successfully? We really need this wireless mesh connection

2. We suspected that T301n were sometime kicked out of the controller

Team, any useful clues on how to solve these issues will be highly appreciated, we need to deliver on this project.